Composite material consisting of intermetallic phases and ceramics and production method for said material

ABSTRACT

The invention concerns a composite material consisting of intermetallic phases and ceramic, in particular in the form of a coating on metallic substrates, as well as an arc wire spraying process for production of the composite material in which the intermetallic phases and the ceramics to be deposited are newly formed during the deposit process from the components of the supplied wires by chemical reaction. The invention further concerns wear resistant layers formed by the composites, tribologic layers and plating or hard-facing materials.

CROSS REFERENCE TO RELATED APPLICATION

This application is a national stage of PCT/DE2004/000221 filed Feb. 9,2004 and based upon DE 103 06 919.4 filed Feb. 19, 2003 under theInternational Convention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention concerns a composite material comprising intermetallicphases and ceramic, in particular in the form of a coating on a metallicsubstrate, as well as an arc wire spraying process for production of thecomposite material in which the intermetallic phases and the ceramics tobe deposited are newly formed during the deposit process from thecomponents of the supplied wires by chemical reaction. The inventionfurther concerns wear resistant layers formed by the composites,tribologic layers and plating or hard-facing materials.

2. Related Art of the Invention

In the production of material layers, the arc wire spraying process orthe thermal spray process is characterized by a simple processmanagement and high deposit rate. The coating of components close totheir final contours of economical materials by means of arc wirespraying (LDS) satisfies many aspects of the requirements for productionof series components and thus is broadly employed in series manufactureapplications. The production of thin metallic layers constitutes thestate of the art. For each spray pass (coating cycle) layer thicknessesof approximately 0.05 to 0.3 mm are achieved. Greater layer thicknessesmust be prepared by multi-layer coating, that is, multiple coatingcycles. LDS is one typical process for manufacture of thin layers.

Greater layer thickness, for example the possibility of the manufactureof entire components, can be accomplished by spray compacting by meansof thermal spraying. Therein the materials are sprayed as powder or wirein a flame or an arc and processed into semi-finished components.

A disadvantage of the LDS spray layers and the spray compacting forproduction of layers and semi-finished products are, until now, theinsufficient adhesion of the layers to the base material (substrate),the high brittleness, the high porosity and the inhomogeneities of thelayers. Particularly disturbing is the tendency towards formation ofcracks in thicker layers, that is, greater than 1 mm thickness.

The basic principle of LDS is at the time strongly limited by theselection of materials for formation of the layers, since the wirematerials must be electrically conductive, as well as meltable under theprocess conditions. Thus, primarily only metallic materials areemployed, as the case may be, metallic layers are produced. Ceramic hightemperature materials are hardly utilizable in this process.

The particularly suited materials include composite materials ofmetal/ceramic, intermetallic/ceramic (intermetallic phases/ceramic) orintermetallic/metal.

From the Patent DE 198 41 618 C2 an LDS process for production oftribologic coatings of a metal/ceramic composite material forsynchronizer rings is known. The wear resistant layer typically contains40 wt. % TiO₂ and the metals Sn, Zn, Cu and/or Al. The porosity isapproximately 20%. The deposit of this composite layer occurs preferablyby spraying a filled wire comprising a metallic jacket of Cu and/or Aland a filling of TiO₂, as well as the metals Sn, Zn, Cu and/or Al. TheTiO₂ ceramic content of the filled wire and deposited layer remainessentially unchanged. The high hardness with simultaneous highresistance to breakage (ductility) required for wear protective layers,semi-finished products for friction systems or protective platings forballistic applications is not satisfactorily achieved by these compositematerials. Likewise, the porosity is too high.

SUMMARY OF THE INVENTION

It is thus the task of the invention to provide a temperature stable andwear resistant component, or a corresponding material layer of acomposite material, which exhibits high hardness with simultaneouslyhigh ductility, as well as an economical and rapid process for themanufacture or depositing thereof.

This task is solved by the provision of a composite material ofintermetallic phases and ceramic phases, of which the components are atleast partially newly formed by the high temperature reaction betweenone metal or the main component of a metal alloy and ceramic particlesduring deposit via LDS, as well as by an LDS process in which the atleast one composite wire of metal or metal alloy and ceramic particlesis employed in the manner such that, by the high temperature reactionbetween metal or metal alloy and ceramic particles during thedepositing, spray particles with new intermetallic phases and newceramic phases are formed.

The inventive LDS process includes therewith a reaction, in particular ahigh temperature reaction, between the individual components of the atleast one supplied composite wire, so that newly formed materials existin the deposited layer. The newly formed materials include intermetallicphases and ceramics. Therein the components can be supplied, besides bythe at least one composite wire, also by further composite wires or byone or more solid wires, that is, purely metallic wires.

The reaction scheme for the main reaction during the LDS process betweenthe metals or metal alloys and the ceramic particles can be summarizedas follows:M+M{grave over ( )}_(a)X_(b)→M_(c)M{grave over ( )}_(d)+M_(e)X_(f)

-   M: Metal (in certain cases as an alloy component)-   M{grave over ( )}: Metal-   X: Non-Metal-   M{grave over ( )}_(a)X_(b) and M_(e)X_(f): Ceramic-   M_(c)M{grave over ( )}_(d): Intermetallic phase (intermetallic)

One concrete example of a reaction is represented by the reactionbetween metallic aluminum and titanium oxide.7 Al+3 TiO₂→2 Al₂O₃+3 TiAl

By the inventive LDS process the material combinations for the compositematerial are provided in a quality, in which they would in other waysnot be obtainable. This applies in particular to high meltingintermetallics and ceramics, as well as in particular measure to notunpyrolyzed meltable compounds.

The inventive composite material is provided, as a result of themanufacturing process, first as material layer. Since the materialhowever can be deposited quasi unlimited in a substantially constantremaining quality, the layer thickness is in principle not limited.Therewith the layered thickness can be substantially above that of thethickness of the substrate. The so-called layer can thus also be viewedor considered as a stand-alone material or as the case may be astand-alone component. In certain cases the substrate can also becompletely removed, in order that the separated layer is obtained asseparate component.

The inventive composite material contains as intermetallic phases(intermetallics), newly formed as a result of the LDS process, compoundsof at least two elements of the group Al, Ti, V, Fe, Co, Ni, Cr, Mo, W,Si or B.

For systematic reasons also the corresponding binary or multinarysilicides or borides are listed or included in the intermetallic phases,since according to the inventive reaction scheme in the LDS processsilicides and borides are also obtainable from the metallic and ceramiccomponents of the sprayed wire. Also, on the basis of their chemicalcharacteristics, these compounds are closer to the intermetallics thanto the typical ceramics.

Preferably the composite material includes one or more of theintermetallic phases titanium aluminide, titanium silicide, nickelaluminide, NiTi-intermetallics, molybdenum silicide and/or titaniumboride. The indicated material coatings include all intermetallic phasesoccurring in the corresponding material system. Particularly preferredare the following compounds individually or in combination: TiAl, TiAl₃,NiAl, NiTi, NiTi₂, NiTi₃, Ni₄Ti₃, TiSi, Ti₅Si₃, MoSi, V₅Si₃, TiB, TiB₂.

The proportion of the intermetallics in the inventive composite materialis above 20 vol. %. The content of intermetallics however preferablylies in the range of 30 to 80 vol. %.

Regarding the intermetallics occurring in the composite material, theseneed not be exclusively the intermetallics newly formed in the LDSprocess. The LDS process is likewise suited to co-deposit intermetallicswhich already exist in the spray wire. Their proportion is howeveroutweighed by the proportion of the newly formed intermetallics formedin accordance with the invention. At least 70 vol. % of theintermetallics contained in the composite material are thus newlyformed.

Further, the inventive composite material contains, as ceramic phasesnewly formed in the LDS process, oxides, nitrides, carbides, silicidesand/or borides of at least one of the elements of the group Al, Ni, Fe,Ti, Co, Mo or W. Preferably the composite material contains at least onenewly formed ceramic phase of Ti- or Al-oxide, or nitride, in particularAl₂O₃, AlN, TiO₂ or TiN.

Included among the newly formed ceramic phases are those which incertain cases are formed by a reaction or transformation between metalor metal alloy and the carrier gas or a reactive component of thecarrier gas during the LDS process. These include in particular theoxides or nitrides which are formed by reaction with or transforming ofthe metal or the metal alloy with oxygen or nitrogen in the carrier gas.The typical composite formed in the high temperature reaction inherentin the inventive LDS process produced typical composite and the typicalmaterial characteristics are also achieved by the direct reactionbetween metal (or as the case may be metal alloy) and oxygen ornitrogen, since these reactions are also involved in high temperaturereactions.

The proportion of the ceramics, in certain cases ceramic particles, inthe inventive composite material is preferably below 80 vol. %.Preferably their content lies in the range of 20 to 70 vol. %. Theceramic component is therein comprised of the newly formed ceramics, aswell as in certain cases residues of not transformed ceramic particlesof the composite wire. In accordance with the invention the proportionof the newly formed ceramic is above 70 vol. % of the total ceramiccontent.

In a preferred embodiment the inventive composite material is built upessentially of Al containing intermetallic phases and Al₂O₃ containingceramic phases, which are produced by a high temperature reactionbetween Al, the metal or metal alloy and an oxidizing ceramic powder.Particularly preferably the intermetallic phase is TiAl and/or Ti₃Al andthe ceramic phase is Al₂O₃.

Preferably the composition of the inventive material is so selected,that it includes only a small content of low-melting phases, inparticular metals or alloys. This is naturally to be achieved by a highconversion of the employed metal or metal alloys with the employedceramic particles. The maximal permissible content of metal in thedeposited material depends upon the later purpose of employment,conventionally however lies below 10 vol. %. For wear protective layersor tribologic layers, metal contents of below 5 vol. % are preferred. Incontrast to the conventional thermal spray process, in accordance withthe inventive process it is also possible to obtainintermetallic/ceramic composite materials with metal contents of below 2vol. %.

Preferably the composite materials exhibit a comparatively high density,as the case may be low porosity. For the employment as wear resistantlayer, tribologic layer or protective plating the closed porosity ispreferably below 5 vol. %.

In a particularly advantageous embodiment of the inventive compositematerial, at least 50 wt. % intermetallic phases are formed of titaniumaluminides and at least 20 wt. % ceramic phases are formed of aluminumoxide. The content of metallic aluminum (meaning herein in particularnot the Al found in intermetallics) lies therein below 2 wt. % and theclosed porosity is therein maximally 5 vol. %.

The thickness of the inventive layer on the substrate, or also theunsupported layer, lies above approximately 0.05 mm. This lower valueresults from the lower-most or smallest technically useful deposit rateof the LDS process. The layer thickness preferably lies however above0.5 mm.

The thickness of the material layer is dictated essentially by thedesired purpose of use. In the case of the wear protective layer, thelayer thickness preferably lies in the range of between 0.5 to 3 mm, fortribologic layers, for example as friction layer for brakes or clutchdiscs, preferably at 0.5 to 5 mm, and for protective plating, forexample as armor material for ballistic applications, preferably at 3 to50 mm.

As substrate for the depositing of the layer, all materials areconsidered suitable which also are suited for the known thermal sprayprocesses. Typically the substrates are metallic materials or ceramicmaterials. Fiber-reinforced ceramics are particularly suited for this.

In certain cases it is useful to employ, between the substrate and theinventive layer, an intermediate layer for promoting adhesion or forbalancing varying thermal physical characteristics. Preferably theintermediate layer is at least partially comprised of a metalliccomponent of the metal or metal alloy supplied to the LDS process.Particularly preferred is when the intermediate layer is formed of thematerial which in the inventive LDS process reacts with or istransformable with the ceramic particles. For iron metal or steelsubstrates, Cr or Ni containing intermediate layers are particularlysuited.

The inventive LDS process envisions employing at least one compositewire of metal or metal alloy and ceramic particles in the manner that,during the depositing, spray particles with new intermetallic phases andnew ceramic phases are formed. The formation of these new compoundsoccurs therein essentially by a high temperature reaction between themetal or the metal alloy and the ceramic particles which are suppliedvia the at least one composite wire.

The inventive LDS process can be carried out with one wire as well aswith two or more wires. The metallic components can be supplied thereinby the at least one composite wire, as well as with also furthercomposite wires or also by one or more solid wires, that is, purelymetallic wires. The ceramic components are preferably supplied in theform of composite wires (metal/ceramic-composite wires).

An essential requirement for the carrying out of the LDS process is thatthe wire or wires exhibit a sufficient electrical conductivity forignition of the arc.

Preferably two wires are employed wherein one first wire is metal or ametal alloy as solid (metal) wire and a second wire as composite wire.

BRIEF DESCRIPTION OF THE DRAWINGS

The following schematic drawings further explain the subject matter ofthe invention.

FIG. 1 Shows a micrograph of an inventive coating according toillustrative embodiment 1, with the substrate of grey cast iron (1), anadhesive layer (2) of NiTi₅ and a composite material layer (3), whichincludes phases of titanium aluminide and Al₂O₃ (4), NiTi₅ (5), nickelaluminide (6) and TiO₂ (7)

FIG. 2 Shows schematically a composite wire of a metal jacket (8) and acore (9) of ceramic powder and composite wire (10) of metal anddispersed ceramic phase.

FIG. 3 Shows a schematic of a cross section through a brake disc segmentwith a core (11) of gray cast iron, adhesive promoting layers (12) andcomposite material layers (13) which respectively are provided upon thetwo oppositely lying friction layers.

FIG. 4 Shows the schematic construction of an armor plate with graduatedbuilding-up of the composite material layer in cross section with a baseplate (14) of steel and three composite material layers (13, 13′, 13″)with varying composition, wherein the ceramic content increases in thesequence from (13″) towards (13′) towards (13).

DETAILED DESCRIPTION OF THE INVENTION

The composite wire (FIG. 1) is conventionally a metal shell 8 withceramic core 9. Suitable composite wires can be produced in accordancewith conventional processes. Thus, it is possible for example to producethe composite wire by stretching a ceramic-particle-filled metal jacketor by roller shaping a ceramic powder coated metal film. Likewise, metalwires with incorporated or embedded dispersed ceramic phases 10 aresuitable.

The principle of LDS the process requires that at least one of thesupplied wires has a sufficient conductivity in order to ignite the arc.In principle thus also combinations of at least one metal conductivewire and a poorly or not conductive wire would be suitable for carryingout the LDS process. Thus, the inventive LDS process also includescombinations of at least one conductive wire and, further, essentiallyceramic comprising wires (ceramic wires). The ceramic wire can thereinbe comprised of pure ceramic, for example ceramic fiber or ceramic fiberbundles, as well as of adhesive-bound ceramic particles. As adhesives,organic polymers and/or metals can be employed.

For the inventive process, as starting components, those materialcombinations of metal and ceramic are particularly suited which in ahigh temperature reaction can be transformed or reacted with each other.Many of the suitable material combinations are known for example fromthe so-called SHS processes, “Self-propagating High temperatureSynthesis”. Therein the known syntheses include both pure solid/solidreactions as well as solid/gas reactions.

As metallic component of the composite wire, or as the solid wire, theelements Al, Ti, Si, V, Cr, Mo, W, Fe, Co or Ni, individually, incombination or as alloys are suited. Particularly preferred are Al, andMg- and/or Si-containing Al-alloys.

As ceramic components of the composite wire, in particular the oxides ofthe element Ti, Zr, Fe, the nitrides of the elements Ti, Zr, Si, SiC,and the borides of the elements Si or Al are suited.

In accordance with the invention, the proportion of the ceramiccomponent in the composite wire lies between 1 and 50 vol. %,particularly preferably between 20 and 40 vol. %.

Particularly preferred is the composite wire of an external metallicjacket 8 and a core 9 of ceramic particles, wherein the cross section ofthe core lies in the range of 20 to 60% of the total cross section.

As diameter and geometric design of the wire, the embodiments known forthe conventional spray process are suitable. Preferably the compositewire is round and exhibits a diameter in the range of 1.2 to 5 mm.

The combination of metal or metal alloy and ceramic must in accordancewith the invention be so selected, that a high temperature reaction issupported with formation of the new intermetallic and ceramic phases.Thus, the following metal (metal alloy)/ceramic combinations are inparticular suitable, which can be employed individually or incombination:

Metal Components Ceramic Components Al TiO₂ Ti SiC Ti Si₃N₄ Al Si₃N₄ AlTiN B TiO₂ NiAl TiB₂ Al, Ti TiO₂ Al, Ti SiC Al, Ti Si₃N₄ Al, Ti B₄C Al,Ti B₂O₃

In a further advantageous embodiment of the inventive process themetallic starting components are so selected, that these are also suitedby reaction with each other to form new intermetallic phases. As furtherhigh temperature reactions occurring during the LDS process, thereoccurs the formation of intermetallics by transformation of metalliccomponents. For this, the metallic components could be contained in thecomposite wire as well as in the solid wire. The combination of elementsfor formation of supplemental intermetallics suitable in particular inaccordance with the inventive process are described in the following,wherein the corresponding elements can be supplied as metal or metalalloy in at least one composite or solid wire:

Metal Component 1 Metal Component 2 Al B Al Ni Ti Si Ti B V Si

In a further embodiment of the invention a carrier gas is employed inthe LDS process, which is suitable for reaction with at least one of themetallic components of the at least one supplied wire. As carrier gas inparticular at least stoichiometric amounts of O₂, CO₂ or N₂ areemployed, which can react with one of the metallic components, inparticular Al or Ti for oxidation, carbonitriding and/or nitriding. Thetransformation of the metal and the reactive component of the carriergas is therein supported by the simultaneously occurring hightemperature reaction between metal and ceramic. By this alternativeembodiment it is possible to further reduce the content of free metals.Since the free metals, such as for example Al, in general in theinventive composite material represent the component with the lowestmelting point and with the lowest high temperature resistance, it is ofsubstantial advantage to keep the amount of their component in thecomposite material as low as possible. Even under very optimal processconditions a complete transformation between the metal or metal alloyand the ceramic to the intermetallics and the new ceramic is notaccomplished, so that metal residues or traces remain. The proportion ofthis metal residue can be further reduced by transformation or reactionwith the reactive component of the carrier gas in the LDS process. Thefree metals are heated so long and to the extent by the high temperaturereaction in the spray particles that they, at least in the outer surfacezone of the particle, are converted to the corresponding oxides and/ornitrides.

In the use of the system with Al as metal and TiO₂ as ceramic preferablya small amount of O₂ component is supplementally added to the carriergas, or the spray stream is so directed, that a certain mixing throughwith the O₂ containing environmental air can occur in the deposit zoneof the spray particles.

As carrier gas, or as the case may be as the main component thereof, ingeneral N₂ can be employed, since the nitride formation of the mostinventive preferred metallic components in contrast to othertransformations is kinetically inhibited, for as the case may be, theformation of the intermetallics of metal and ceramic occur substantiallymore rapidly and preferably.

The chemical reactions leading to the formation of the intermetallics isstrongly exothermic and causes a very strong heating of the sprayparticles. The reaction partially continues also into the freshlydeposited layer. This has the advantage, that the energy input via theLDS spray nozzle in the spray material can be reduced and that theparticles remain in part liquid or soft even into the deposit zone.Thereby the particles can be deformed and can form a very dense metallayer. The deposited particles can, on the basis of their hightemperature, also in part sinter together or weld together. Inparticular, material combinations which contain Al or Al alloys as metalcomponents of at least one wire lead to comparatively dense layers.

The process leads in general to a porosity of the deposited compositematerial of less than 5 volume percent. The high material density (lowporosity) achievable by the inventive LDS process provides a furthergreat advantage in comparison to many of the conventional thermal sprayprocesses.

The composition of the composite material is in particular adjusted bythe relationship of the components supplied by means of the at least onewire. The adjustment of the relationship of the components to each othercan occur in various ways.

-   -   The build up or, as the case may be, the composition of the        composite wire, for example the relationship between metallic        jacket and ceramic core.    -   Various diameters or cross sectional surfaces in the case of        multiple wires.    -   Varying rates of feed in the case of multiple wires.

In general, a dosing or feeding of the individual components inprecisely stoichiometric ratio is not necessary. Preferably, themetallic components are employed non-stoichiometrically, in order toreduce the residual content of free metal in the composite material. Incomparison to this, the residue of non-transformed ceramic is in generalsubstantially less damaging for the characteristics of the compositematerial, since even the starting ceramic exhibits as a rule clearly abetter high temperature survivability and wear resistance than themetallic components. Preferably the components are supplied to the LDSprocess in such a ratio, that the residual content of free metal isbelow 5 vol. % and the residual content of not transformed ceramic isless than 10 vol. %.

It is particularly preferred to introduce the metallic and ceramiccomponents via the wires in an amount relationship in the LDS process sothat at least the metallic components are completely transformed to newceramics and/or intermetallics.

In particular in the case of different supply speeds of the wires it isachievable in simple manner by the change of the speed during thedeposit process to achieve a local change in the composition of thecomposite material, in particular a gradient configuration or build-up.

In one particularly advantageous embodiment of the invention, in a workprocess first a metallic adhesive promoting layer is deposited andthereupon the inventive composite material is deposited, wherein thechemical composition of the adhesion promoting layer graduallytransitions into the composite material layer.

A further aspect of the invention concerns the use of the inventivecomposite material layers, or as the case may be the inventive compositematerial.

The composite material layers are exceptionally suited as wear resistantlayers. In particular, layers are available which exhibit a combinationof good tribologic and good wear resistance characteristics. These canbe employed for example as friction layers for brakes, clutches andlinings. Particularly suited therefore are the TiAl and Al₂O₃ containingcomposite materials. A particularly preferred application concerns brakediscs of iron or steel with friction surfaces of the inventive compositematerial layer.

The combination of high hardness and ductility imparts to the compositematerial good resistance against ballistic influences. In particular theTiAl- and titanium silicide and/or titanium boride including systems arevery suitable as ballistic protective armor plating. A particularadvantage of the inventive process is that even complex shapedcomponents or layers can be produced on complex shaped substrates insimple manner. This is in particular of interest for the armor platingof motor vehicles or in aviation, where complex subassemblies can nolonger be protected usefully by conventional armor plates. The ballisticcharacteristics can be further improved by the employment of ceramic orfiber reinforced ceramic as substrate.

ILLUSTRATIVE EXAMPLE 1

This illustrative Example is concerned with the manufacture of a highcapacity brake disc for motor vehicles. For this, the brake disc wasproduced by the combination of a conventional gray cast iron brake discwith a friction layer of a titanium aluminide/aluminum oxide compositematerial. A conventional gray cast iron brake disc was prepared forcoating by sandblasting. For the LDS process two different wires wereemployed. Wire 1, the metallic wire, was comprised of conventionalNiTi₅. Wire 2, the composite wire, was comprised of a metallic jacketand a ceramic core. The metallic jacket was formed by Al (purity greaterthan 99.5%) and the core by titanium oxide (TiO₂) particles (Rutil) withan average particle size in the range of 2 to 5 μm. The wire wascomposed of 72 wt. % of jacket material and 28 wt. % filler. The wirewas obtained by stretching a titanium oxide particle filled aluminummetal jacket.

The diameter of both wires was 1.6 mm.

For coating, conventional LDS equipment was employed, wherein nitrogenwas employed as carrier gas. In a first process variant the LDS processwas first started with only wire 1 and a NiTi adhesive layer with alayer thickness of 0.1 mm was deposited. Thereupon the process wasswitched to depositing with the two wires. Therein the supply rate ofthe wires was so adjusted that the relationship of wire 2(Al/TiO₂-composite wire) to wire 1 (Ni₅) in the reaction zone wasapproximately 20. By multiple passing over of the substrate with thespray jet a layer thickness of 1.5 mm was deposited.

The residual porosity of the deposited composite material layer,measured as closed porosity, was approximately 2 vol. %.

The micrograph of a cross section through the deposited layer is shownin FIG. 1. In the deposited layer (3) individual phases of titaniumaluminide/Al₂O₃ (4) NiTi (5), nickelaluminide (6), and TiO₂ (7) can beseen. The phases exhibit an elongated structure and a very tight anddense packing, as is typical for the depositing of liquid mushymaterial. By the high temperature reactions in the particles asufficiently high temperature continuing to the point of deposit isfinally guaranteed or accomplished. On the micrograph no porosity is tobe recognized within the deposited layer.

A further brake disc was produced with the same conditions exceptwithout the intermediate layer.

Both brake discs were ground planar and flat in conventional manner. Thetesting of the characteristics occurred in a friction evaluator usingmass produced brake liners. The friction layers exhibited temperatureresistance up to 1100° C. in air and showed good friction values, aswell as an exceptional wear resistance.

ILLUSTRATIVE EXAMPLE 2

Illustrative Example 2 concerns the manufacture of a shaft of a spraycompacted bolt provided with a wear resistant coating.

As base or substrate for building the bolt a steel plate with a groundsurface was employed. Thereupon, by spray compacting in known manner inmultiple layers, a bolt or stud is deposited.

The wear resistant protective layer was produced by the inventive LDSprocess with two wires. As wire 1 a conventional NiTi₅ wire with adiameter of 1.5 mm was employed. As wire 2 a composite wire comprised of65 wt. % Al (purity 99.5%)and 35 wt. % titanium oxide (Rutil, with anaverage particle diameter of 2 to 5 μm) was employed. The Al formed adense jacket for the core comprised of titanium oxide. The diameter ofthe composite wire was 2 mm. The two wires were supplied to theLDS-nozzle with the same and constant speed.

For examination of the material characteristics of the depositedcomposite material, the bolt and substrate were removed with machiningfrom the layer. The remaining composite material layer was ground orhoned. The mechanical characteristics of the composite material layerproduced a hardness of 350 MPa and a breaking elongation of 0.35%.

1. A process for producing a layer of a composite material of metallic,intermetallic and ceramic phases by depositing the layer formingcomponents by means of arc wire spraying with at least one compositewire of metal or metal alloy and ceramic particles, wherein thesecomposite wire components undergo reactions with each other duringdepositing forming intermetallic phases and new ceramic phases, whereinmore than 70 vol. % of the ceramic particles undergo reactions duringthe spray processing with formation of intermetallic phases and newceramic phases, and wherein the metal or the metal alloy of thecomposite wire reacts to the extent that unreacted metal or metal alloyconstitutes less than 10 vol. % of the formed composite material.
 2. Theprocess according to claim 1, wherein additional metallic solid wire isemployed, and wherein at least one of the metallic components of thesolid wire reacts with a ceramic powder of the composite wire.
 3. Theprocess according to claim 1, wherein the development of exothermic heatas a result of the reaction continues in part also in the newlydeposited layer.
 4. The process according to claim 1, wherein thecomposite wire includes as metallic component at least Al, Ti, Ni, Fe,Co, Ni, Mo and/or W as metal or their alloys, as well as titanium oxide,zirconium oxide, boroxide, iron oxide, nickel oxide, silicium carbide,silicium nitride and/or borocarbide as ceramic component.
 5. The processaccording to claim 1, wherein the composite wire comprises a metalliccoating or jacket and a ceramic filler.
 6. The process according toclaim 1, wherein the composite wire includes a ceramic component of 20to 40 vol. %.
 7. The process according to claim , wherein during the arcwire spraying intermetallic phases of at least two elements from thegroup Al, B, Ni, Fe, Ti, Co, Mo, W, Si, B are newly formed in the sprayparticles.
 8. The process according to claim 1, wherein during the arcwire spraying in the spray particles ceramic phases of aluminum oxide,titanium carbide, titanium boride, titanium silicide and/or titaniumnitride are newly formed.
 9. The process according to claim 8, whereinthe reaction with the reactive gas leads to metal oxides and/or metalnitrides.
 10. The process according to claim 1, wherein during the arcwire spray process reactive gasses are supplied, which react with atleast one of the metallic components of the at least one suppliedcomposite wire.
 11. The process according to claim 1, wherein after thereaction to the new intermetallic phases or ceramic phases remainingfree aluminum in the deposited layer is essentially converted toaluminum oxide.
 12. A composite material of metallic, intermetallic andceramic phases formed by depositing the layer forming components bymeans of arc wire spraying with at least one composite wire of metal ormetal alloy and ceramic particles, wherein these composite wirecomponents undergo reactions during depositing forming intermetallicphases and new ceramic phases, wherein more than 70 vol. % of theceramic particles undergo reactions during the spray processing withformation of intermetallic phases and new ceramic phases, and whereinthe metal or the metal alloy of the composite wire reacts to the extentthat unreacted metal or metal alloy constitutes less than 10 vol. % ofthe formed composite material.
 13. The composite material according toclaim 12, wherein the intermetallic phases newly formed by arc wirespraying and deposited are comprised of at least two elements of thegroup Al, B, V, Ni, Fe, Ti, Co, Cr, Mo, W, Si or B.
 14. The compositematerial according to claim 12, wherein the intermetallic phases includetitanium aluminide, titanium silicide, nickel aluminide, NiTiintermetallics, molybdenumsilicide and/or titanium boride.
 15. Thecomposite material according to claim 12, wherein the ceramic phasesdeposited by the arc wire spraying include oxides, nitrides, carbides,silicides and/or borides.
 16. The composite material according to claim12 the ceramic phases newly formed and deposited by arc wire sprayinginclude aluminum oxide, titanium carbide, titanium silicide, titaniumcarbide and/or titanium nitride.
 17. The composite material according toclaim 12, wherein a ceramic content of 10 to 70 wt. % and a content ofintermetallic phases of 30 to 90 wt. %, as well as a porosity of lessthan 7 Vol. %.
 18. The composite material according to claim 12, whereinit has a content of free metallic aluminum of less than 2 wt. %.
 19. Thecomposite material according to claim 12, wherein it is provideddeposited in a thickness of greater than 5 mm on a metallic substrate.20. The composite material according to claim 12, wherein said materialconstitutes a as friction layer for brake components or a wear resistantlayer in motor vehicle.
 21. The composite material according to claim12, wherein said material constitutes a plating or protective layeragainst ballistic effect.
 22. A composite material of metallic,intermetallic and ceramic phases formed by depositing the layer formingcomponents by means of arc wire spraying with at least one compositewire of metal or metal alloy and ceramic particles, wherein thesecomposite wire components undergo reactions with each other duringdepositing forming intermetallic phases and new ceramic phases, whereinmore than 70 vol. % of the ceramic particles undergo reactions duringthe spray processing with formation of intermetallic phases and newceramic phases, and wherein the metal or the metal alloy of thecomposite wire reacts to the extent that unreacted metal or metal alloyconstitutes less than 10 vol. % of the formed composite material,characterized by at least 50 wt. % intermetallic phases of titaniumaluminides; at least 20 wt. % intermetallic phases of nickel aluminides;at least 20 wt. % ceramic phases of aluminum oxide; and at most 5 vol. %closed porosity.